Abstract

1. Dobutamine in 5% (w/v) d-glucose was infused at sequential doses of 2, 5 and 10 μg min−1 kg−1, 45 min at each dose, into eight healthy male subjects, and the effects were compared with those produced by infusion of the corresponding volumes of 5% (w/v) d-glucose alone.

2. The energy expenditure increased and was 33% higher than control (P<0.001) at 10 μg of dobutamine min−1 kg−1. The respiratory exchange ratio decreased from 0.85 (sem 0.02) before infusion to 0.80 (sem 0.01) at 10 μg of dobutamine min−1 kg−1, but did not alter during the placebo infusion (P> 0.001).

3. Plasma noradrenaline concentrations were lower during the dobutamine infusion compared with during the infusion of d-glucose alone (P < 0.025). Plasma dopamine concentrations remained below 0.1 nmol/l throughout both infusions.